Slider for bolting-screens.



A. JOHNSTON & P. B. PEOK.

SLIDER FOR BOLTING SCREENS. APPLICATION um JULY 14, 1909.

Patented Jan. 18, 1910.

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by reason of the nature of their structure.

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ALLEN JOHNSTON, 0F OTTUMWA, IOWA, AND FRANK IB. PECK, OF MOUNT VERNON, MISSOURI.

SLIDER FOR BOLTING-SCREENS.

To all whom it may concern:

Be it known that we, ALLEN JOHNSTON, of Ottumwa, Iowa, and FRANK B. Pack, of Mount Vernon, Missouri, have invented a new and useful Improvement in Sliders for Bolting-Screens, which invention is fully set forth in the following specification.

This invention relates to improvements in devices designed particularly to be used in connection with flour bolting screens or plan flour sifters to facilitate breaking up the flakes of flour delivered from the rolls, while insuring a free and open condition of the bolting cloth of the screens.

I-Ieretofore it has been proposed to place on the bolting screen with the flour to be bolted freely movable bodies such as rubber balls, for the purpose of jarring, by their bouncing action, the bolting cloth to facilitate the passage of the flour particles through the meshes of the fine screen. To effect a proper jolting action to the bolting cloth, the individual mass of each ball has been made sufficient to give, by reason of its momentum, a decided blow to the screen. Owing to the delicate nature of the screen material, a large number of such balls could not be supported on the bolting cloth, and their action was confined almost exclusively to keeping the meshes of the fabric open, and failed to effect proper attrition of the flour flakes. To secure a more effective attrition of the flakes, beans and grains of corn have been employed on the screens. A serious disadvantage resulted from their use,

The horny shell or casing of the beans or grains of corn would wear through in spots, leaving a softer material exposed to wear. Sharp cutting edges resulted where these openings occurred in the beans, which first roughened the threads of the fabric, causing the meshes to retain the flour, thereby retarding bolting action, and secondly these sharp edges of the beans finally cut the threads and destroyed the proper mesh formation of the screen, and prevented proper separation of the flour and bran.

Our invention has for its object to provide light metallic bodies, preferably hollow and formed from sheet metal, such as steel, and adapted by reason of their configura tion to slide over the horizontal surface of a sifter, such as the bolting cloth in a plan sifter and to effect on the flour flakes a roller Specification of Letters Patent.

Application filed July 14, 1909.

Patented Jan. 18, 1910. Serial No. 507,643.

' grinding action to break up and distribute the flakes and force the particles of flour through the meshes of the bolt. By reason of the extreme lightness of these bodies, large numbers of them may be employed on the bolting screen Without danger of overweighting the fabric, thereby enormously nmltiplying the working surfaces and enabling an effective attrition of the flour flakes, while maintaining a free and open condition of the meshes of the sieve without roughening or cutting the threads of the bolting cloth. Since these metallic bodies, which we shall hereafter refer to as sliders, can be struck up from sheet metal, we are enabled to make them of uniform size, and give to them a configuration peculiarly adapted to break up the flakes of flour and clean the bolt. The longer these sliders are used, the smoother they become, thereby developing less wear in the bolting cloth, and

reducing the number of stoppages for re- .the use of our improvement.

lVhile we may give to these sliders a variety of forms, some of these forms we have illustrated by way of example in the accompanying drawings, to which reference is had for assisting the description of the invention.

Figure 1 is a plan view of a bolting screen provided with our improvement; Fig. 2 is a longitudinal sectional view on line 22 of Fig. 1; Fig. 3 is a perspective view of a sheet metal blank from which the slider is made; Fig. 4 is a view in sectional elevation showing one stage in the manufacture; Fig. 5 is a view in central vertical section through one form of our completed slider; Fig. 6 is a perspective view of the slider shown in Fig. 5; Figs. 7 and 8 illustrate in vertical sectional views other embodiments of our improvement.

Referring to Fig. 1, we have therein shown a double plan flour sifter, one side of which is right-handed and the other side lefthanded, consisting of a frame 1, divided lengthwise by a partition 2 into two longitudinal compartments extending nearly the full length of the sifter. Attached to the underside and central portion of the frame 1 is bolting cloth 3 forming the bottom of the sifter. Atthe receiving or right-hand end of the sifter is an imperforate floor 4, preferably of tin, and at the right of this tin floor, is a coarse screen bottom Each of the two main compartments of the sifter is divided longitudinally into a tortuous channel by plates 6, 6. which terminate short of the left-hand end of the sifter. At the entrance ends of these channels, and over the tin floor, are gates or valves 7, 7, through which the flour drops into the sifter, which is assumed to have a counter-clockwise gyratory movement. imparted to it by means not shown but well understood in this art. To assist the materials to move in their respective channels clockwise and counter-clockwise. as indicated by the arrows 8. S, we provide flights 9. 9, which project into the channels and are so located on the partitions and walls. having in view their action on the materials while subject to a left-handed gyratory movement, as to urge the material forward as indicated by the arrows.

In F 3 to 8. we have illustrated the manner of constructing our sliders and some of the forms which they may assume. \Ve pref erably take a square sheet metal blank of thin sheet steel 10, though other metals may be used, such as zinc, aluminum, brass or the like, but we prefer steel because of its hardness and magnetic susceptibility, and upset the blank in a die press to give it the form of a cup 11. as shown in Fig. 4. The serrated edges of the cup are brought together and made to assume a smooth spherical shape under the action of a suitably shaped die, while the bottom of. the cup is slightly flattened, and preferably indented at 12. as shown in Fig. The center of gravity of this form of slider is nearer the flattened side, thereby enabling the slider to present its flattened sliding side to the bolting cloth when placed in the sifter and under the action of its gyratory movement.

The form of slider shown in Fig. 5 presenting an indented sliding surface possesses this advantage: \Vhile there is less rubbing surface exposed in the indented slider, the indentation or cavity appears to hold the tlour flakes 'aught under the moving slider to better advantage against the meshes of the screen, whereby, as tests in actual practice show, there is a gain in yield of bolted flour. The size of this form of slider may vary, depending on the nature of the material subjected to attrition. In the case of flour, we prefer to make the longest diameter about i to an inch, though we do not limit ourselves in this respect.

In operation, a quantity of the sliders are placed on the screen suflicient in number to distribute themselves over the surface of the bolting cloth. Under the action of the sifter, each slider assumes a position of stable equilibrium with its flattened side next the cloth. The flour which is fed to the I sifter through the gates flows in the 1 direction of the arrows under action of the gyrating movement of the sifter assisted by the flights 9. 9, and mingles with the sliders distributed over the bolting cloth. The flour flakes are ground between the rolling surfaces of adjacent sliders, and are, to a certain extent, battered to pieces as they are caught between the impacting bodies, while the resulting flour particles are rubbed through the meshes of the bolt by the fiattened sliding surfaces as the sliders move forward with the flour stream. At the exit ends of the channels the chaff and sliders move onto the coarse sieve 5 which retains the sliders and drops the chaff. The sliders so are now ready for renewed use. here steel or iron is used in their construction, magnetic devices may be employed for their separation from the chaff or from the flour in case of accident to the sieve.

In Fig. 7 we have shown a lenticular slider having the serrations slightly incurved to prevent them from catching in the threads of the cloth. The form shown in Fig. 8 is j similar to that of Fig. 7 except the bottom is indented and the serrations are somewhat more incurved.

Vhile the forms shown in Figs. 7 and 8 require less care in their manufacture, we prefer the embodiment shown in Figs. 1 to 6 for the reasons noted above, and since we are able to bring the edges of the cup 11 into perfect contact while preserving a spherical contour to the top of the slider.

What is claimed is 1.. An article for use on bolting screens to break up flour flakes and to keep the meshes of the screen open, consisting of a sheet metal body presenting a flattened sliding surface, and aroller acting surface.

2. An article for use on bolting screens to break up flour flakes and to keep the meshes of the screen open, consisting of a sheet metal body presenting an indented flattenec sliding surface, and a roller acting surface.

3. A slider for use in bolting flour, consisting of a single sheet of metal formed into a hollow body having a flattened sliding surface, and a. roller acting surface. 7

l. A slider for use in bolting flour, consisting of sheet metal formed into a closed hollow body having a single flattened sliding surface, and a round roller acting surface.

A slider for use in bolting flour, consisting of sheet metal formed into a body having a flattened concave sliding surface, and a round roller acting surface.

6. A slider for use in bolting flour, consisting of a single piece of sheet steel formed j i into a closed hollow body, said body having a sliding surface and a roller acting surface.

7. A slider for use in bolting flour, consisting of a hollow sheet metal body having a roller acting surface.

8. An article for use in bolting screens to break up flour flakes and to keep the meshes of the screen 0 en, consisting of a hollow sheet metal bocy having a single flattened sliding surface.

9. A slider for use in bolting flour consisting of a hollow sheet metal body having a flattened sliding surface.

10. A slider for use in bolting flour, cona flattened indented sliding surface.

11. An article of the character described, consisting of a single sheet of metal formed into a closed hollow body having an integral flattened sliding surface.

19. A slider for use in bolting flour consisting of a hollow indented sheet metal bodv.

13. A ,slider for use in bolting flour, consisting of a hollow sheet metal body having a flattened indented side.

14. A slider for use in bolting flour, consisting of a hollow sheet metal body having a flattened side.

In testimony whereof We have signed this 1 specification in the presence of tWo subscribsisting of a hollow sheet metal body having ing witnesses.

ALLEN JOHNSTON. FRANK B. PEG-K. lVitnesses as to Allen Johnston:

THOS. Ronenns,

PEARL DE NOON. lVitnesses as to Frank B. Peck:

J. M. MoPHERsoN,

A. L. HELPERT. 

